Inflammation occurs in response to benign vocal fold diseases, bacterial and viral infections, reflux, phonotrauma and surgery and can lead to scarring, a common cause of intractable dysphonia. Little is known about the role of the epithelium in modulating the inflammatory response. Our long term goal is to improve prevention and management of vocal fold pathologies by identifying and manipulating the manner in which epithelial cell-fibroblast interactions modulate healthy and aberrant mucosal healing following injury, infection, inflammation, and irritation. The overall goal of this projectis to identify and characterize the role of epithelial cell-fibroblast interactions in initiating the inflammatory response in the early stages of wound healing. We will develop a physiologically relevant, three-dimensional vocal fold mucosa model populated by novel epithelial cell lines. We will use this model to examine the role of epithelial cells in initiating and sustaining the inflammatory responses in a wound healing model. Our working hypothesize is that injury to the epithelium will induce epithelial cells to secrete pro-inflammatory cytokines, chemokines and growth factors. This inflammatory response will activate fibroblasts inducing fibroblast proliferation, and extracellular matrix protein production. In specific aims 1 and 2, we will creat a continuous supply of robust epithelial cell lines through i. guided differentiation of human induced pluripotent stem cells into epithelial cells and ii. immortalization of human primary epithelial cells. We will validate the cell lines through side-by-side comparisons of the complete gene profile of the cell lines and primary human vocal fold epithelial cells. We anticipate that th gene mapping data and cell lines generated in this project will be highly valuable to other scientists and have included a data sharing plan to make our raw data, cell lines available to the scientific community. In specific aim 3, we will create an in vitro model of vocal fold mucosa populated by a continuous supply of stable epithelial cells and fibroblasts. We will evaluate paracrine signaling interactions between epithelial cells and fibroblasts in responses to a scratch-wound to the epithelium. Specifically, we will identify the impact of the pro-inflammatory and regenerative epithelial responses to injury on fibroblast activation, proliferation, and extracellular matrix protein production. Our findings will provide the necessary ground work for manipulating cell signal pathways to promote rapid, complete restoration of vocal fold function following injury, irritation or disease. Use of a biomimetic in vitro model of human origin for stuy of vocal fold injury will reduce the need for animal trials and concerns regarding species-specific differences in healing responses. Additional contributions of this innovative work are expected to be the use of our reproducible and valid three-dimensional model populated by novel epithelial cell lines to model disease processes and to develop, test, and facilitate translational applications of cytoprotective and regenerative treatments for damaged or diseased vocal folds.